Perceptual phenomena after unilateral arm amputation: a pre-post-surgical comparison

Painful and non-painful phantom phenomena occur frequently after amputations but are rarely investigated in the perioperative stage. The goal of the present study was the assessment of phantom phenomena, pain and changes in primary somatosensory cortex prior to and after upper limb amputation. Two patients who suffered from metastatic carcinoma were examined 2 days prior to and 7 days after the amputation of an arm using comprehensive psychometric assessments and neuroelectric source imaging. Both patients reported phantom limb pain that was similar to their pre-amputation pain. In one patient, reorganization of the mouth area into the deafferented hand area took place immediately after the amputation. In the other patient reorganization had occurred prior to the amputation possibly related to non-use of the arm several years prior to the amputation

Fear conditioning in psychopaths: Event-related potentials and peripheral measures

AbstractAversive pavlovian delay conditioning was investigated in a sample of 11 criminal psychopaths as identified by using the Psychopathy Checklist-Revised and 11 matched healthy controls. A painful electric stimulus served as unconditioned stimulus and neutral faces as conditioned stimuli. Event-related potentials, startle response potentiation, skin conductance response, corrugator activity, and heart rate were assessed, along with valence, arousal, and contingency ratings of the CS and US. Compared to healthy controls, psychopathic subjects failed to differentiate between the CS+/CS− as shown by an absence of a conditioned response in startle potentiation and skin conductance measures. Through use of a fear-eliciting US, these data confirm previous findings of a deficient capacity to form associations between neutral and aversive events in psychopathy that appears unrelated to cognitive deficits and is consistent with hypothesized frontolimbic deficits in the disorder

Pain therapy in addicted patients

Each individual is entitled to an adequate and sufficient pain therapy. However, only a few studies have examined the peculiarities of pain management in drug-dependent or formerly addicted patients. Any addiction is disadvantageous for a successful pain therapy, since some of the prescribed drugs may themselves cause addiction. Drug-dependent patients are often tolerant to opioids. Additionally, there is a risk of iatrogenic pain becoming chronic due to disregard for already known risk factors and comorbidities.However, a history of addiction should not prevent sufficient pain therapy, especially since there is no risk of addiction when the pain therapy employed is adequate for the pathophysiology involved. There are adequate pain therapies for addicted patients. The best results are achieved by taking into account the physiological and psychological peculiarities of drug-dependent patients. Importantly, this should be combined with a variety of different, optimized, multimodal therapeutic regimes, as well as with an interdisciplinary approach